150 SUPPLExMENT TO THE BRITISH 



123. Terebratula globata, var. Birdlipensis, Walker MS. Sup., PI. XVII, figs. 18, 



19, 20,21. 



This fossil (according to Mr. J. F. Walker) is the variety pointed out by Dr. 

 Lycett at p. 134 of his " Cotteswold Hills " as differing from Sowerby's species. 1 I 

 quite concur in the view he has taken in the matter. The shell is elongated, oval, with 

 very convex, almost gibbous valves, and when full grown is massive. The dorsal valve 

 is very much swollen out, especially at and near the umbone, uniformly convex to 

 within one half and sometimes two thirds of its length. When the valves become 

 gradually biplicated the two folds are rounded, close to each other, and separated by a 

 deepish sinus of about the breadth of one of the folds. The ventral valve is very deep 

 and uniformly convex to about one third of its length from the beak, when a rounded, 

 longitudinal, mesial fold gradually rises and extends to the front ; on either side a narrow, 

 concave depression corresponds to the fold on the dorsal valve. The beak is large and 

 broadly rounded, incurved, and truncated by a circular foramen lying close to the umbone 

 of the dorsal valve; frontal line strongly bisinuate, and often very much thickened. 

 Surface smooth ; loop short. Proportions variable ; an average-sized specimen measured — 

 Length 1 inch 5 lines ; width 1 inch ; depth about the same. 

 Obs. — This well-marked variety occurs abundantly in the Clypeus-grit of the Inferior 

 Oolite at Birdlip Hill, near Cheltenham. It differs from Sowerby's T. globata in being 

 more elongated, and the anterior folds are more strongly defined. It is also more 

 globose. Specimens of this variety were found by Mr. J. F. Walker in a blue rock at 

 the base of the Fuller's-earth Oolite at Sapperton Tunnel, Gloucestershire. 



124. Terebratula Bradfordiensis, Walker MS. Dav., Sup., PI. XVII, fig. 6. 



Shell sub-pentagonal, longer than wide, biplicated close to the frontal margin, 

 tapering towards the beak, plications rounded, frontal line bisinuated ; valves very 

 moderately convex, somewhat flattened; beak incurved, and truncated by a circular 

 foramen lying close to the hinge-line ; loop short ; surface smooth. 

 Length 9, width 8, depth 4 lines. 

 Obs. — Since I alluded to this shell at p. 140 of this Supplement Mr. J. F. Walker has 

 given it the name of Bradfordiensis. He considers it to be specifically separable from 

 Ter. Ferrt/i, as it is always small, remarkably flat, and the plications are not so extended. 



1 The larger specimen alluded to at p. 136, PI. XVII, fig. 1, of this Supplement is a large form of 

 a variety of T. globata, differing from the Sowerby type in some particulars. 



